vaadin/flow

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Vaadin Flow is a Java framework binding Vaadin web components to Java. This is part of Vaadin 10+.

Stars: 754
Forks: 219
Open beginner issues: 2
Indexed issues: 1.3k
Avg merge: 21h 25m
Merged PRs (30d): 401

Dominant language: Java
License: Apache-2.0
Last GitHub push: Sep 19, 2026
Latest indexed: Sep 19, 2026
Contributing guide: Contributing guide
Code of conduct: No code of conduct
Beginner labels: help wanted good first issue

Beginner friendly Everything

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1,281 open issues indexed

Allow @JsInvoker to target a @JsModule Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

vaadin/flow#25814 · 1 comment · Opened Sep 18, 2026
Call instance method for @JsInvoker methods without a @JsExpression annotation Open

Difficulty 3/5 1-2 days Newbie friendliness 72/100

vaadin/flow#25812 · 1 comment · Opened Sep 18, 2026
Support typed return values from @JsInvoker methods Open

Difficulty 3/5 1-2 days Newbie friendliness 58/100

vaadin/flow#25811 · 1 comment · Opened Sep 18, 2026
Split @JsInvoker code in the JS bundle using the same logic as @JsModule splitting Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

vaadin/flow#25810 · 1 comment · Opened Sep 18, 2026
Automate the maintained-branch health check Open

internal improvement

Difficulty 5/5 Over a week Newbie friendliness 25/100

vaadin/flow#25778 · 1 comment · Opened Sep 17, 2026
[aw] Failed jobs: Documentation Bot Open

agentic-workflows

Difficulty 3/5 1-2 days Newbie friendliness 35/100

vaadin/flow#25770 · Opened Sep 16, 2026
Make framework-generated JavaScript invocations identifiable to an external test driver Open

Difficulty 5/5 Over a week Newbie friendliness 48/100

vaadin/flow#25734 · 1 comment · Opened Sep 15, 2026
[aw] Failed jobs: Documentation Bot Open

agentic-workflows

Difficulty 4/5 3-5 days Newbie friendliness 25/100

vaadin/flow#25726 · 1 comment · Opened Sep 15, 2026
Dev loop: a Kotlin source edit is silently skipped — apply reports "no changes" with exit 0 Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

vaadin/flow#25716 · 1 comment · Opened Sep 15, 2026
Loading indicator is set to opacity 0 and pointer-events none for all stages Open

Difficulty 3/5 1-2 days Newbie friendliness 68/100

vaadin/flow#25705 · 1 comment · Opened Sep 14, 2026
Route path is decoded twice when it reaches the router already decoded Open

Difficulty 5/5 Over a week Newbie friendliness 38/100

vaadin/flow#25690 · 1 comment · Opened Sep 12, 2026
Add support for passing parameters to event data expressions Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

vaadin/flow#25658 · 4 comments · Opened Sep 11, 2026
Store theme names in a node feature like ClassList instead of parsing the theme attribute Open

breaking change element API internal improvement

Difficulty 4/5 3-5 days Newbie friendliness 48/100

vaadin/flow#25603 · 1 comment · Opened Sep 9, 2026
Hackathon 25.3: Four older behaviours that cost a real application time Open

Difficulty 5/5 Over a week Newbie friendliness 38/100

vaadin/flow#25580 · 3 comments · Opened Sep 9, 2026
Hackathon 25.3: MenuConfiguration.getPageHeader calls a title generator with no route parameters Open

Difficulty 3/5 1-2 days Newbie friendliness 70/100

vaadin/flow#25578 · 1 comment · Opened Sep 9, 2026
Hackathon 25.3: CSS files pulled in with @import from a stylesheet are blocked by the default security setup Open

documentation

Difficulty 3/5 1-2 days Newbie friendliness 72/100

vaadin/flow#25576 · 1 comment · Opened Sep 9, 2026
Hackathon 25.3: no server side way to build a route's absolute URL Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

vaadin/flow#25574 · 3 comments · Opened Sep 9, 2026
Hackathon 25.3: Three deprecations that do not name a replacement Open

documentation

Difficulty 4/5 3-5 days Newbie friendliness 48/100

vaadin/flow#25571 · 1 comment · Opened Sep 9, 2026
Hackathon 25.3: FeatureFlags.setEnabled rewrites the project's source file Open

documentation

Difficulty 3/5 1-2 days Newbie friendliness 68/100

vaadin/flow#25567 · 2 comments · Opened Sep 9, 2026
Hackathon 25.3: A PageTitleGenerator annotated @Component silently becomes the whole application's generator Open

Impact: Low Severity: Minor

Difficulty 4/5 3-5 days Newbie friendliness 55/100

vaadin/flow#25558 · 1 comment · Opened Sep 9, 2026
Notify VaadinService initialization listeners after the outermost `init()` has finished Open

v26

Difficulty 4/5 3-5 days Newbie friendliness 45/100

vaadin/flow#25555 · Opened Sep 9, 2026
Integrate CLI and daemon to vaadin-agent-tools Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

vaadin/flow#25462 · Opened Sep 3, 2026
Automatic tests for Vite/Hotdeploy mode covering TS/JS changes/hot-reload Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

vaadin/flow#25461 · Opened Sep 3, 2026
Automatic tests for Windows script Open

Difficulty 3/5 1-2 days Newbie friendliness 25/100

vaadin/flow#25460 · Opened Sep 3, 2026
Support for non-Spring application servers Open

vaadin/flow#25458 · 1 assignee · Opened Sep 3, 2026
PiT 25.3: applications cannot keep their own TypeScript version, so typescript-eslint stops installing Open

bug Impact: Low node/npm/pnpm/bun Severity: Major workaround

Difficulty 4/5 3-5 days Newbie friendliness 45/100

vaadin/flow#25416 · 4 comments · Opened Sep 1, 2026
Changes to the Dialog are not reflected in the UI after HotSwap Open

Impact: Low live reload Severity: Minor

Difficulty 4/5 3-5 days Newbie friendliness 55/100

vaadin/flow#25415 · 1 comment · Opened Sep 1, 2026
Change “Native” prefixed html wrappers to “Html” Open

v26

Difficulty 4/5 3-5 days Newbie friendliness 42/100

vaadin/flow#25401 · 2 comments · Opened Aug 31, 2026
Warn if the same component instance has multiple signal effects with the same effect callback Open

Complexity: Low signals

Difficulty 5/5 Over a week Newbie friendliness 35/100

vaadin/flow#25302 · 3 comments · Opened Aug 25, 2026
Support coding agent daemon to work with Gradle Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

vaadin/flow#25280 · Opened Aug 21, 2026
Using daemon with coding agent and app running from IDE in debug mode Open

Difficulty 5/5 Over a week Newbie friendliness 30/100

vaadin/flow#25279 · 1 comment · Opened Aug 21, 2026
Allow ServiceInitListeners to decorate the executor VaadinService resolves Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

vaadin/flow#25253 · Opened Aug 19, 2026
VaadinSession.getPushId calls checkHasLock although not needed. Open

investigation

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

vaadin/flow#25233 · 4 comments · Opened Aug 17, 2026
Click shortcut on a button inside a modal Dialog no longer fires after opening the dialog Open

Impact: Low regression Severity: Major

Difficulty 3/5 1-2 days Newbie friendliness 74/100

vaadin/flow#25213 · 4 comments · 1 reaction · Opened Aug 13, 2026
Coding agents have no reliable feedback loop for changes to a running dev-mode app Open

Epic

vaadin/flow#25197 · 2 comments · 1 reaction · 1 assignee · Opened Aug 12, 2026
PWA app's content starts below "dynamic island" when not using AppLayout Open

Impact: Low Severity: Major workaround

Difficulty 3/5 1-2 days Newbie friendliness 65/100

vaadin/flow#25177 · 4 comments · Opened Aug 11, 2026
Add ability to make some views live only in DEV Mode Open

Difficulty 5/5 Over a week Newbie friendliness 45/100

vaadin/flow#25170 · 8 comments · Opened Aug 10, 2026
addToModalComponent does not nest overlays inside VISUAL modals Open

investigation

Difficulty 3/5 1-2 days Newbie friendliness 68/100

vaadin/flow#25136 · 1 comment · Opened Aug 5, 2026
Do not destroy existing `pnpm-workspace.yml` file Open

Complexity: Medium Impact: Low node/npm/pnpm/bun Severity: Minor

Difficulty 4/5 3-5 days Newbie friendliness 48/100

vaadin/flow#25122 · 2 comments · Opened Aug 3, 2026
Separate framework bookkeeping of pending JavaScript invocations from the public then() API Open

refactor

Difficulty 4/5 3-5 days Newbie friendliness 52/100

vaadin/flow#25096 · Opened Jul 31, 2026
Make application configuration global Open

Complexity: High needs design v26

Difficulty 5/5 Over a week Newbie friendliness 25/100

vaadin/flow#25090 · Opened Jul 31, 2026
Thick Scrollbar Open

question theming

Difficulty 4/5 3-5 days Newbie friendliness 52/100

vaadin/flow#25085 · 12 comments · 2 reactions · Opened Jul 30, 2026
Enable `VaadinService` initialization for unit tests with a server key in commercially maintained versions Open

Complexity: Medium

Difficulty 5/5 Over a week Newbie friendliness 38/100

vaadin/flow#25075 · Opened Jul 30, 2026
Gradle: do not run vaadinPrepareFrontend when production mode is active Open

gradle

Difficulty 3/5 1-2 days Newbie friendliness 68/100

vaadin/flow#25074 · Opened Jul 30, 2026
Allow multiple uses of the @EnableVaadin annotation. Open

spring

Difficulty 3/5 1-2 days Newbie friendliness 68/100

vaadin/flow#25022 · Opened Jul 21, 2026
Public API to move a component subtree to another UI (so @PreserveOnRefresh isn't the only cross-UI transfer path) Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

vaadin/flow#25019 · 1 reaction · Opened Jul 21, 2026
Make it possible to supply a custom VaadinServletContextInitializer Open

spring

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

vaadin/flow#25007 · 2 comments · Opened Jul 20, 2026
Expose resolved Flow RouterLayout chain in NavigationContext Open

access-control Complexity: Low navigation

Difficulty 3/5 1-2 days Newbie friendliness 62/100

vaadin/flow#24985 · Opened Jul 14, 2026
Add an AfterReloadEvent Open

preserve-on-refresh routing

Difficulty 5/5 Over a week Newbie friendliness 35/100

vaadin/flow#24970 · 6 comments · Opened Jul 13, 2026
Copilot devToolsPlugins.push crashes production builds when devToolsPlugins array is never initialized Open

investigation waiting for author

Difficulty 4/5 3-5 days Newbie friendliness 55/100

vaadin/flow#24963 · 2 comments · Opened Jul 12, 2026

vaadin/flow

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